Metalworking fluid used in metalworking and subsequent washing is generally categorized into oil-type fluid and water-type fluid, the latter of which is more frequently used because such water-type fluid is excellent in cooling capabilities and infiltration capabilities and free from a risk of causing a fire. In general, stock solution of water-type cutting oil, grinding oil and washing oil is diluted with water to a ratio from 1:1 to 1:200 in use.
When emulsion-type aqueous machining oil is used in the manufacturing process of the automobiles or machine components, cut powders and surface stickiness remain after being dried without applying any treatment. Thus, no-rinse washing is often applied in the subsequent processes using solution-type aqueous detergent (aqueous detergent). The rinsing is omitted in order to reduce waste fluid disposal amount.
For instance, in order to degrease metal, ceramics and the like, an aqueous detergent containing a polyalkylene glycol and non-ionic surface-active agent has been proposed (see Patent Literature 1).